I have a scripting system that works well using userdata objects. However, now I want to have a property in my user data that can take a regular table.
I think I need to create a regular table and set the metatet to use my current set of metamethods, but I'm struggling to figure out how to do this - I'm sure this is a simple setup, I just can "Look right now."
My existing code looks like this:
void
LuaContext::push(lua_State* state, boost::shared_ptr<LuaWrapped> wrapped) {
static struct luaL_Reg methods[] = {
{ "__index", LuaWrapped::static_get },
{ "__newindex", LuaWrapped::static_set },
{ "__len", LuaWrapped::static_len },
{ "__ipairs", LuaWrapped::static_ipairs },
{ "__pairs", LuaWrapped::static_pairs },
{ "__gc", LuaWrapped::static_gc },
{ "__eq", LuaWrapped::static_eq },
{ NULL, NULL }
};
LuaWrapped::Ptr **ptr = (LuaWrapped::Ptr **)lua_newuserdata(state, sizeof(LuaWrapped::Ptr *));
*ptr = new LuaWrapped::Ptr(wrapped);
if (luaL_newmetatable(state, "LuaWrapped")) {
lua_pushstring(state, "__index");
lua_pushvalue(state, -2);
lua_settable(state, -3);
luaL_openlib(state, NULL, methods, 0);
}
lua_setmetatable(state, -2);
}
The metamethod __gcis there to remove the class LuaWrapped::Ptr(which is a wrapper for boost::shared_ptr). I think I will leave this and save the pointer in the lightuserdata field in a regular table.
( ):
void
LuaContext::push(lua_State* state, boost::shared_ptr<LuaWrapped> wrapped) {
static struct luaL_Reg methods[] = {
{ "__index", LuaWrapped::static_get },
{ "__newindex", LuaWrapped::static_set },
{ "__len", LuaWrapped::static_len },
{ "__ipairs", LuaWrapped::static_ipairs },
{ "__pairs", LuaWrapped::static_pairs },
{ "__gc", LuaWrapped::static_gc },
{ "__eq", LuaWrapped::static_eq },
{ NULL, NULL }
};
lua_newtable(state);
LuaContext::push(state, "pointer");
lua_pushlightuserdata(state, new LuaWrapped::Ptr(wrapped));
lua_settable(state, -3);
lua_newtable(state);
luaL_openlib(state, NULL, methods, 0);
lua_setmetatable(state, -2);
}
int
LuaWrapped::static_get(lua_State* state) {
int argc = lua_gettop(state);
for (int i = 1; i <= argc; i++) {
const char *type = lua_typename(state, i);
std::cout << type << std::endl;
}
....
:
,
get (Lua 5.2, Ubuntu 14.04):
boolean, userdatap >